Chapter 18, Problem 83A

Interpretation Introduction

Interpretation:

The solution having greater $\left[H^{+}\right]$ is to be determined and $pH$ values are to be calculated.

Concept introduction:

$pH$ gives the concentration of hydrogen ion in a solution.

It tells about acidity and basicity of a solution.

It is given by:

$\begin{array}{l}pH=-\log \left[H^{+}\right]\\ pOH=-\log \left[O{H}^{-}\right]\\ pH+pOH=14\\ \left[H^{+}\right]isconcentationofhydrogenions\\ \left[O{H}^{-}\right]isconcentationofhydroxylions\end{array}$

Answer to Problem 83A

$HCl$ has greater hydrogen ion concentration

$p{H}_{HCl}=1$

$p{H}_{HF}=2.1$

Explanation of Solution

$\begin{array}{l}\left[HCl\right]=0.10M\\ {\left[H^{+}\right]}_{HF}=7.9\times {10}^{-3}M\end{array}$

$HCl$is strong acid. Therefore, $\left[HCl\right]=\left[H^{+}\right]$

So, $\left[H^{+}\right]=0.10M$

$\begin{array}{c}p{H}_{HCl}=-\log (0.10)\\ =1\end{array}$

$\begin{array}{c}p{H}_{HF}=-\log (7.9\times {10}^{-3})\\ =-\log 7.9-\log {10}^{-3}\\ =0.9-3\\ =2.1\end{array}$

$HCl$ has greater hydrogen ion concentration because it has lesser $pH$

Conclusion

Thus,

$HCl$ has greater hydrogen ion concentration

$p{H}_{HCl}=1$

$p{H}_{HF}=2.1$